futuristic mod set in a dystopian world

Hello everyone! I've been planning on making a futuristic mod set in a dystopian world for a few years now. I've already figured out a lot of things, story wise. But now, I finally want to do some modding, and I'm stumped. I don't know which modding tool to use! I know, I'm greedy and everything, but I really need a powerful toolset that isn't too hard to use, and has good support. So, I've listed a few, and I could really use your opinion. If you think there are other and better toolsets, feel free to list them. Thank you.